1. Field of the Invention
This invention relates to the field of fishing tools. More specifically, the present invention comprises a tool for equilibrating the internal pressure of a fish brought up from “depth.”
2. Description of the Related Art
Most fish use swim bladders to control their buoyancy. A fish normally expels air from its swim bladder as it returns to the surface from depth such that the volume of air in the fish's swim bladder remains relatively constant. When fishing at depths greater than 30 feet, it is not uncommon to bring a fish to the surface at such a fast rate that the fish's swim bladder overexpands (due to the decreasing pressure of water on the fish) and pours out of the fish's body cavity. While this does not pose a significant problem for fish that are kept by the fisherman, many fish pulled from depth must be released back into the water. This most often occurs because the fish is too small to legally keep without violating a size limit law or because keeping the fish would cause the fisherman to exceed a bag limit law. These released fish have a low probability of survival because of their inability to return to depth rapidly.
Only a few tools are currently marketed or otherwise available for equilibrating a fish's swim bladder before it is released. These devices typically include a puncturer which is used to perforate the swim bladder of the fish allowing the excess air to escape. Several such devices illustrated and described in U.S. Pat. No. 6,065,238 to Carter et al. Such devices suffer from similar shortcomings. First, some devices employ a fixed, exposed puncturer. These devices can be dangerous to use on a boat where the motion of the boat and slippery conditions can cause the fisherman to inadvertently puncture himself or another person on the boat with the tool. In order to make these devices safer, some employ puncturers which are excessively dull. Dull puncturers are difficult to use, however, because more force is required to push the puncturer through the body of the fish.
In order to alleviate the problems associated with such devices that employ fixed, exposed puncturers, Carter et al. proposed a tool which uses a moveable puncturer which moves between a covered state and an uncovered state. This design is illustrated in FIGS. 5 and 6 of the Carter et al. patent. This design is problematic, however, because the user's thumb must cover the ventilating orifice to hold the puncturer in the uncovered state.
As such, it would be beneficial to provide an equilibrating tool which is easy and safe to use.